vehicle purchases, increased interest rates may also decrease vehicle sales, which would negatively affect our operating results.
Impairment of our goodwill or other indefinite-lived intangible assets has in the past had, and in the future could have, a material adverse impact on our earnings. We evaluate goodwill and other indefinite-lived intangible assets for impairment annually and upon the occurrence of an indicator of impairment. Our process for impairment testing of these assets is described further under “Impairment Testing” in Part II, Item 7, Management’s Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates. If we determine that the amount of our goodwill or other indefinite-lived intangible assets are impaired at any point in time, we would be required to reduce the value of these assets on our balance sheet, which would also result in a material non-cash impairment charge that could also have a material adverse effect on our results of operations for the period in which the impairment occurs.
Performance of sublessees. In connection with the sale, relocation and closure of certain of our franchises, we have entered into a number of third-party sublease agreements. The rent paid by our sub-tenants on such properties in 2016 totaled approximately $20.6 million. In the aggregate, we remain ultimately liable for approximately $211.4 million of such lease payments including payments relating to all available renewal periods. We rely on our sub-tenants to pay the rent and maintain the properties covered by these leases. In the event a subtenant does not perform under the terms of their lease with us, we could be required to fulfill such obligations, which could have a significant and adverse effect on us.
Information technology. Our information systems are fully integrated into our operations and we rely on them to operate effectively, including with respect to: electronic communications and data transfer protocols with manufacturers and other vendors; customer relationship management; sales and service scheduling; data storage; and financial and operational reporting. The majority of our systems are licensed from third parties, the most significant of which are provided by a limited number of suppliers in the U.S., U.K. and Australia. The failure of our information systems to perform as designed, the failure to protect the integrity of these systems, or the interruption of these systems due to natural disasters, power loss or other reasons, could disrupt our business operations, impact sales and results of operations, expose us to customer or third-party claims, or result in adverse publicity.
Cyber-security. As part of our business model, we receive personal information regarding customers, associates and vendors, from various online and offline channels. We collect, process, and retain this information in the normal course of our business. Our internal and third-party systems are under a moderate level of risk from hackers or other individuals with malicious intent to gain unauthorized access to our systems. Cyber-attacks are growing in number and sophistication thus presenting an ongoing threat to systems, whether internal or external, used to operate the business on a day to day basis. Despite the security measures we have in place, our facilities and systems, and those of our third-party service providers, could be vulnerable to security breaches, computer viruses, lost or misplaced data, programming errors, human errors, acts of vandalism, or other events. Any security breach or event resulting in the misappropriation, loss, or other unauthorized disclosure of confidential information, or degradation of services provided by critical business systems, whether by us directly or our third-party service providers, could adversely affect our business operations, sales, reputation with current and potential customers, associates or vendors, as well as other operational and financial impacts derived from investigations, litigation, imposition of penalties or other means.
The United Kingdom’s potential departure from the European Union could adversely affect us. The United Kingdom held a referendum on June 23, 2016 in which a majority voted to exit the European Union (“Brexit”). Although the vote is non-binding, negotiations are expected to commence at some point in the future to determine the future terms of the United Kingdom’s relationship with the European Union, including, among other things, the terms of trade between the United Kingdom and the European Union. The effects of Brexit will depend on any agreements the United Kingdom makes to retain access to European Union markets either during a transitional period or more permanently. Brexit itself and the length of time the United Kingdom and the European Union engage in discussions, which could be over a protracted period of time, could adversely affect European and worldwide economic and market conditions and could contribute to instability in global financial and foreign exchange markets, including volatility in the value of the Sterling and Euro.